MODIFICATION OF THE EYE PEDUNCLES IN CYJIONOMUS. 457 



The i-ostrnm is reduced to a small process in the mid-frontal 

 line (see PI. 34, fig. 8) : two other forms of the diminutive 

 rostrum are seen in PI. 34, figs. 10 and 11, thus necessitating 

 the emendation of the character as to the size and form of 

 the rostrum by which the tribe Cyclodorippje were supposed 

 to be separated from the tribe of the Cymonoraas. 



The ocular peduncles of C. Normani have moved from 

 the lateral position which they occupy in C. granulatus, 

 and approach the middle line from each side. Their bases 

 are actually fused to one another beneath the rudimentary 

 rostrum, and they are immovably united to the margin of the 

 carapace (see PI. 39, fig. 8). Further, the free diverging^ 

 stems of the ocular peduncles differ greatly in form from those 

 of C. granulatus. Like those of C. quadratus, they are 

 entirely devoid of a corneal area, and taper gradually to the 

 extremity. But, unlike those of C. quadratus, the ocular 

 peduncles of C. Normani are not straight, and denticulate 

 on the inner face only. They present, on the contrary, a 

 curvature, first inwards, then outwards, and then again 

 strongly inwards at the extremity (PI. 34, fig. 10). They 

 are very much more richly beset with spinules than are the 

 ocular peduncles of C. granulatus, and the spinules are of 

 larger size. 



Speaking generally, the spinules on the frontal region of 

 the carapace, extra-orbital spines, basal antennary joints, 

 and eye peduncles are coarser and more exuberant in C. 

 Normani than in 0. granulatus. As shown in PI. 34, 

 fig. 8, the theoretical third (the actual second) joint of 

 the antennary peduncle, a", is fringed externally with spines 

 in C. Normani; these are wanting in C. granulatus (PI. 



34, fig. 7, a"). 



Distribution. — Only three specimens of this species are 

 known, viz. those originally dredged by the Rev. Canon 

 Norman on the Holtenia ground in 1869 in the cruise of the 

 " Porcupine." 



' Not, united to form a single lostruni as Dr. Norniau's briel' description 

 had led some of his readers to suppose. 



